FrameCollection: implements ArrayAccess

src/Whoops/Exception/FrameCollection.php

@@ -9,6 +9,7 @@ use Whoops\Exception\Frame;
 use UnexpectedValueException;
 use IteratorAggregate;
 use ArrayIterator;
+use ArrayAccess;
 use Serializable;
 use Countable;
 
@@ -16,7 +17,7 @@ use Countable;
  * Exposes a fluent interface for dealing with an ordered list
  * of stack-trace frames.
  */
-class FrameCollection implements IteratorAggregate, Serializable, Countable
+class FrameCollection implements ArrayAccess, IteratorAggregate, Serializable, Countable
 {
     /**
      * @var array[]
@@ -93,6 +94,42 @@ class FrameCollection implements IteratorAggregate, Serializable, Countable
         return new ArrayIterator($this->frames);
     }
 
+    /**
+     * @see ArrayAccess::offsetExists
+     * @param int $offset
+     */
+    public function offsetExists($offset)
+    {
+        return isset($this->frames[$offset]);
+    }
+
+    /**
+     * @see ArrayAccess::offsetGet
+     * @param int $offset
+     */
+    public function offsetGet($offset)
+    {
+        return $this->frames[$offset];
+    }
+
+    /**
+     * @see ArrayAccess::offsetSet
+     * @param int $offset
+     */
+    public function offsetSet($offset, $value)
+    {
+        throw new \Exception(__CLASS__ . ' is read only');
+    }
+
+    /**
+     * @see ArrayAccess::offsetUnset
+     * @param int $offset
+     */
+    public function offsetUnset($offset)
+    {
+        throw new \Exception(__CLASS__ . ' is read only');
+    }
+
     /**
      * @see Countable::count
      * @return int

tests/Whoops/Exception/FrameCollectionTest.php

@@ -61,6 +61,44 @@ class FrameCollectionTest extends TestCase
         return new FrameCollection($frames);
     }
 
+    /**
+     * @covers Whoops\Exception\FrameCollection::offsetExists
+     */
+    public function testArrayAccessExists()
+    {
+        $collection = $this->getFrameCollectionInstance();
+        $this->assertTrue(isset($collection[0]));
+    }
+
+    /**
+     * @covers Whoops\Exception\FrameCollection::offsetGet
+     */
+    public function testArrayAccessGet()
+    {
+        $collection = $this->getFrameCollectionInstance();
+        $this->assertInstanceOf('Whoops\\Exception\\Frame', $collection[0]);
+    }
+
+    /**
+     * @covers Whoops\Exception\FrameCollection::offsetSet
+     * @expectedException Exception
+     */
+    public function testArrayAccessSet()
+    {
+        $collection = $this->getFrameCollectionInstance();
+        $collection[0] = 'foo';
+    }
+
+    /**
+     * @covers Whoops\Exception\FrameCollection::offsetUnset
+     * @expectedException Exception
+     */
+    public function testArrayAccessUnset()
+    {
+        $collection = $this->getFrameCollectionInstance();
+        unset($collection[0]);
+    }
+
     /**
      * @covers Whoops\Exception\FrameCollection::filter
      * @covers Whoops\Exception\FrameCollection::count